Digital Principles and System Design MCQs | Page - 8

 because only concurrent statements can be used, therefore, with-select is the correct alternative for the method used by the user. but, with-select also requires when keyword to implement the selected assignment.

 in a process used for the implementation of the combinational circuit, all the input signals used which are to be read, should appear in its sensitivity list. in a combinational circuit, there can be many inputs and those inputs should appear in the sensitivity list of the process.

 since, 24 = 16, therefore, the decoder can act as hexadecimal to binary converter. because, 4 bits input is converted to 16 bits output. each bit corresponding to 4 output bits. so, clearly it is a hexadecimal to binary convertor.

 latch is a type of bistable multivibrator having two stable states. both inputs of a latch are directly connected to the other’s output. such types of structure is called cross coupling and due to which latches remain in the latched condition.

 the register capable of shifting in one direction is unidirectional shift register. the register capable of shifting in both directions is known as a bidirectional shift register.

 the maximum possible range of bit- count specifically in n-bit binary counter consisting of ‘n’ number of flip-flops is 0 to 2n-1. for say, there is a 2-bit counter, then it will count till 22-1 = 3. thus, it will count from 0 to 3.

 decimal counter is also known as 10 stage counter. so, it has 10 states. it is also known as decade counter counting from 0 to 9.

 it is true that a sequential logic can’t be executed by concurrent statements only. it requires the sequential statements because they make use of a clock signal.

 latch has an enable input, but no clock signal. all other circuits including asynchronous counter needs a clock signal. it is called asynchronous because every flip flop doesn’t have same clock signal.

 since there is only one input to the flip flop, therefore, it can be either d or t flip flop. but, the output becomes equal to the input signal as soon as there is a positive edge of the clock therefore, it is a delay flip flop.